Collins says the views of President Obama's defense secretary nominee on the most critical threats facing the United States are "unsettling.''

WASHINGTON (AP) _ Sen. Susan Collins says she will oppose the confirmation of Chuck Hagel to become President Barack Obama's secretary of defense.

Collins, a moderate Republican from Maine who had been seen as a possible supporter of Hagel, said Wednesday that his views on the most critical threats facing the United States are "unsettling.''

Collins said in a statement that Hagel was unwilling to ask the European Union to designate Hezbollah a terrorist organization in 2006, and he has been hesitant to back the use of all non-military options, such as unilateral sanctions, to pressure Iran into ceasing its nuclear program.

Collins said she would not join in a filibuster to block a final vote.

The Senate Armed Services Committee voted 14-11 on Tuesday to send Hagel's nomination to the full Senate.

Collins' colleague, independent Angus King, was among 14 members of the committee to endorse Hagel's nomination.

"I am convinced that he is a man of honesty and integrity who will work tirelessly to advise the President in his best judgment and who will well lead our brave men and women in the military," King says in a statement.